Convective instability of 3-D fluid-saturated geological fault zones heated from below

We conduct a theoretical analysis to investigate the convective instability of 3-D fluid-saturated geological fault zones when they are heated uniformly from below. In particular, we have derived exact analytical solutions for the critical Rayleigh numbers of different convective flow structures. Using these critical Rayleigh numbers, three interesting convective flow structures have been identified in a geological fault zone system. It has been recognized that the critical Rayleigh numbers of the system have a minimum value only for the fault zone of infinite length, in which the corresponding convective flow structure is a 2-D slender-circle flow. However, if the length of the fault zone is finite, the convective flow in the system must be 3-D. Even if the length of the fault zone is infinite, since the minimum critical Rayleigh number for the 2-D slender-circle flow structure is so close to that for the 3-D convective flow structure, the system may have almost the same chance to pick up the 3-D convective flow structures. Also, because the convection modes are so close for the 3-D convective flow structures, the convective flow may evolve into the 3-D finger-like structures, especially for the case of the fault thickness to height ratio approaching zero. This understanding demonstrates the beautiful aspects of the present analytical solution for the convective instability of 3-D geological fault zones, because the present analytical solution is valid for any value of the ratio of the fault height to thickness. Using the present analytical solution, the conditions, under which different convective flow structures may take place, can be easily determined

Hydrodynamic Issues in PAMS Mandrel Target Fabrication

OAK-B135 Imperfections in PAMS mandrels critically govern the quality of final ICF targets. Imperfections in the mandrels can have a wide range of origins. Here, they present observations of 3 types of imperfections, and data to support the proposal that hydrodynamic factors during the curing of the mandrel are potential causes of these imperfections

PERFORMANCE ANALYSIS OF SPECTRAL RESPONSES OF A.CEPA PEEL DYESENSITIZED SOLAR CELLS TO LIQUID ELECTROLYTES

This study investigates the effect of variation of electrolyte on the output performance of A.cepa peel dye-sensitized solar cells. Four A.cepa dye-sensitized solar cells were sensitized with different liquid electrolytes. The criteria used for assessing their performance was the short circuit current (Isc), open circuit voltage (Voc), maximum power (Pmax), fill factor (ff), output efficiency (ƞ) and the incident photon to conversion efficiency (IPCE). The responses produced by the A.cepa dye solar cells were varied. The most efficient electrolyte was Mercury chloride (HgCl2) with an efficiency of 0.27%, potassium bromide (KBr) recorded the highest value in maximum power (Pmax), fill factor (ff) and open circuit voltage (Voc) with the following values: 38.09 W, 2.83 and 700 V respectively. HgCl2 also had the highest Isc, with a value of 0.04 mA and the best IPCE was obtained with KCl with a value of 1.64%. The significance of this outcome is that, HgCl2 and KCl electrolytes influenced the performance of A.cepa peel dye-sensitized solar cell by suppressing dye agglutination while KBr electrolyte improved A.cepa peel dye-sensitized solar cell’s electrochemical stability

Bifurcation in axisymmetric Czochralski natural convection

none2A. BOTTARO; ZEBIB ABottaro, Alessandro; Zebib, A

Three dimensional mixed convection in an inclined pipe

Mixed convection in a cylindrical channel inclined at different angles has been studied computationally. A three-dimensional approach is essential for retaining the features of the flow, which include separation at the wall, fluid moving along spiral paths, and asymmetry. Such characteristics have considerable influence on heat transfer and pressure drop